SrAl2Si2O8增强BN陶瓷的力学性能及抗热震性能

扫码查看

原文链接

万方数据

中文摘要：h-BN陶瓷以其良好的热稳定性和优异的介电性能而成为高超声速飞行器防热透波部件的优异材料,然而h-BN陶瓷烧结致密化相对困难,且力学性能较差.SrAl2Si2O8(SAS)具有较低的熔点和较高的强度,将其引入到h-BN陶瓷中能够起到促进烧结和补强增韧的作用.本研究以h-BN、SrCO3、Al2O3和SiO2为原料,采用热压烧结制备了 BN-SAS复相陶瓷,研究了烧结压力对复相陶瓷显微组织结构、力学性能和热学性能的影响规律,并评价了BN-SAS复相陶瓷的抗热震性能.结果表明,热压烧结制备的BN-SAS复相陶瓷的物相主要为六方氮化硼和六方锶长石.随着烧结压力增大,复相陶瓷的致密度增加,力学性能呈现先增大后略有降低的趋势.在20 MPa烧结压力下制备的复相陶瓷的力学性能最优,其抗弯强度和断裂韧性分别为(138±4)MPa和(1.84±0.05)MPa·m1/2.10 MPa烧结压力下制备的BN-SAS复相陶瓷具有较低的热膨胀系数,在200～1200 ℃范围内的平均热膨胀系数为2.96×10-6 K-1.20 MPa烧结压力下制备的复相陶瓷的热导率较高,室温～1000 ℃时热导率变化范围为12.42～28.42 W·m-1·K-1.BN-SAS复相陶瓷表现出良好的抗热震性能,经600～1400 ℃温差的热震实验后,其残余抗弯强度先增大后迅速降低.复相陶瓷的残余抗弯强度在热震温差为800 ℃时达到最高,残余强度保持率为101％.随着热震温差逐渐增大,陶瓷表面的氧化程度逐步加剧,热应力引起的裂纹逐渐增多.

外文标题：Mechanical Properties and Thermal Shock Resistance of SrAl2Si2O8 Reinforced BN Ceramic Composites

外文摘要：Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric properties.However,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather unsatisfactory.In this study,SrAl2Si2O8(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and toughness.Then,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO3,Al2O3,and SiO2 as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were investigated.The thermal shock resistance of BN-SAS ceramic composites was evaluated.Results show that phases of as-prepared BN-SAS ceramic composites are h-BN and h-SrAl2Si2O8.With the increase of sintering pressure,the composites'densities increase,and the mechanical properties shew a rising trend followed by a slight decline.At a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m12,respectively.Composites sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96× 10-6 K-1 in the temperature range from 200 to 1200 ℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m-1·K-1 within the temperature range from room temperature to 1000 ℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400 ℃.The maximum residual bending strength is recorded at a temperature difference of 800 ℃,with a residual strength retention rate of 101％.As the thermal shock temperature difference increase,the degree of oxidation on the ceramic surface and cracks due to thermal stress are also increased gradually.

外文关键词：

BN matrix compositehot-press sinteringmechanical propertythermal shock resistanceservice reliability

作者：

王博、蔡德龙、朱启帅、李达鑫、杨治华、段小明、李雅楠、王轩、贾德昌、周玉

展开 >

作者单位：

哈尔滨工程大学材料科学与化学工程学院,黑龙江省先进纳米材料联合实验室,哈尔滨 150001

哈尔滨工业大学材料科学与工程学院,先进结构功能一体化材料与绿色制造技术工业和信息化部重点实验室,哈尔滨 150001

华润水泥技术研发有限公司,广州 510000

陆军装备部驻北京地区第一军代处,北京 100072

中国航天科工集团第四研究院第四总体设计部,北京 100048

哈尔滨工业大学(深圳)材料科学与工程学院,深圳 518055

展开 >

关键词：

BN基复相陶瓷热压烧结力学性能抗热震性服役可靠性

基金：

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNatural Science Foundation of Heilongjiang ProvinceScientific and Technological Innovation Leading Talent of Harbin ManufacturingFundamental Research Funds for the Central Universities

项目编号：

5207208852072089LH2023E0612022CXRCCG0013072023CFJ1003

出版年：

2024

DOI：

10.15541/jim20240091

无机材料学报

中国科学院上海硅酸盐研究所

无机材料学报

CSTPCD北大核心

影响因子：0.768

ISSN：1000-324X

年,卷(期)：2024.39(10)